Brush-holder



J. S. DEAN.

BRUSH HOLDER.

APPLICATION FIILED FEB. 3. 1917.

1,361,968. Patented Dem 14, 1920.

F/yl.

E98. J 6 a fifi i i Y I l s E I l l I I I I I WITNESSES: lNVENTOR Jofin 6. Dean.

Q BY a%@% I UNITED STATES JOHN S..DEAN, OF EDGEXVOOD PARK, FENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE PATENT OFFICE.

BRUSH-HOLDER.

Specification of Letters Patent.

Patented Dec. 14;, 1920.

Application filed February 3, 1917. Serial No. 146,438.

To all whom it may concern:

Be it known that 1, JOHN S, DEAN, a citizen of the United States, and a resident of Edgewood Park, in the county of Allegheny and State of Pennsylvania, have invented a newand useful Improvement in Brush- Holders, of which the following is a speci fication.

My invention relates to brush holders for dynamo-electric machines, and it has for its object to provide a brush holder of such form that it will not materially injure the currentdelivering surface of the associated commutator cylinder by accidental engagement therewith.

Brush holders, as heretofore constructed, have usually comprised boxes or receptacles for thebrushes, the lower edges of which were substantially parallel to the surfaces of the associated commutator cylinders. If the brush holder accidentally drops from its supports during operation of the machine, the lower edges of the brush box will engage and damage the surface of the commutator cylinder, particularly the layers of insulation between the conducting segments. The most serious damage occurs within the path ordinarily traversed by the brushes and is caused by the edges of the brush box that extend parallel to the longitudinal axis of the commutator cylinder.

According to the present invention, I provide a brush holder with end projections which prevent accidental engagement between the brush box and the surface of the commutator cylinder within the path ordinarily traversed by the brushes.

In the accompanying drawing, Figure 1 is a view, partially in section and partially in side elevation, of a brush holder embodying my invention, and Fig. 2 is a view, in front elevation, of a portion of the parts shown in Fi 1.

The brush holder comprises a body member 1 provided, at one end, with a brush box 2 and, at the other end, with supporting rods 3. The supporting rods 3 are adapted to be engaged by suitable clamping means (not shown) for maintaining the brush box 2 in spaced parallel relation to the surface of a commutator cylinder 4. Brushes 5 are located in the brush box 2 and are biased toward the commutator cylinder 4 by means of pressure-exerting devices 6. The brushbox 2 is substantially rectangular in form and is provided, along its lower edges, with portions 7 that project beyond the edges 8 of the box which are parallel to the longitudinal axis of the commutator cylinder 1, as best shown in Fig. 2.

From the foregoing, it is apparent that, if the brush box accidentally falls upon the surface of the commutator cylinder 4, the projecting portions 7 will engage the commutating surface at points outside of the path ordinarilytraversed by the brushes 5. Thus, it will be impossible for the parallel edges 8 of the brush-box 2 to engage the surface of the commutator cylinder until the projecting portions 7 have worn a groove on each side of the brush path, as indicated in dotted lines, or until the portions 7, themselves, have been worn off. These conditions are extremely unlikely to occur, as the position of the brush holder would probably be discovered before the portions 7 would have engaged the commutator cylinder for an appreciable length of time. The commutating surface is thus protected from damage within the path normally traversed by the brushes.

While I have shown my invention in its preferred form, it is not so limited but is capable of various minor changes and modifications within the scope of the appended claims.

I claim as my invention:

1. The combination with a commutator cylinder and a brush holder provided with a brush box normally maintained in spaced parallel relation to said cylinder, of projections provided on the transverse edges of said brush box for preventing accidental engagement between the surface of said commutator cylinder within the path normally traversed by the brushes and the edges of said box parallel to the longitudinal axis of said cylinder.

2. The combination with a commutator cylinder, a brush holder provided with a brush box normally maintained in spaced re lation to said cylinder, of projections provided on the edges of said brush box normal to the longitudinal axis of said cylinder for preventing engagement between the surface of said commutator cylinder and the edges of said box parallel to the longitudinal axis of said cylinder.

3. The combination with a commutator cylinder, a brush holder provided with a brush box normally maintained in spaced relation to said cylinder, of projections provided on the edges of said brush box normal to the longitudinal axis of said cylinder and extending on either side of the path on said cylinder normally traversed by said brushes for preventing engagement between the said brush holder and the surface of said commutator cylinder within the said path.

4:. The combination of a commutator cylinder, a brush box provided with a brush, said brush box being normally maintained in spaced relation with said cylinder, and means carried by said brush box for engagement with said cylinder without the path of the brush to prevent engagement between the brush box and the surface of the commutator cylinder.

5. T he combination of a commutator cylinder, a brush box provided with a brush, said brush box being normally maintained in spaced relation with said cylinder, and means carried by said brush box for engagement with said cylinder without the path of the current delivering surface of said commutator cylinder for preventing engagement between the brush box and the surface of said cylinder.

In testimony whereof, I have hereunto subscribed my name this 26th day of J an., 191

JOHN S. DEAN. 

